Liquid-level indicator



Sept.'1s,1928. L 1,685,051

J. GIRARDET LIQUID. LEVEL INDIGTOR- Filed May 19, 1925 Patented sept. 1s,A 192e.

' UNITED rares sereni" Aorrieej JACQUES GIRARDET, or PARS, FRANCE.Y

LIQUID-LEVEL INDICATOR. l i it Application iledMay 19, 1925, Serial No. 31,299, and in' France April 14, '71925.

Known level indicating devices are in use for theV measurement at a distance of the volume of liquid-in a receptacle. these consisting in principle of a .perforated cylinder having the same height as the sa id receptacle and having ai central shaft or upright'upon which is'slidable a suitable float. the latter being guided upon the said shaft while it is also enabledto follow the Vangular movement of the latter.

In this typev of apparatus, the level is vmeasured at a distance by rotating the shatt in such manner as to bring a projection or L ly tappet mounted upon the said float into con# tact Ywitha helical Yramp which is disposeduponthe internal wall-ot the cylinder; the vangle of rotation of thefloat is measured by the displacement of apointer'upon a dial. the apparatus being so arranged that the dial will afford lthe direct reading of the amountl of liquidin the said receptacle.

My invention has for its obje-ct a levelindicating apparatus of this class, .vhie-hotfers the following particular features:

' (a) The loatshatt isrotated by apulley which is provided with a reaction spring and to which is attached the cable ota Bowden power transmission devicewhereof the other `end is disposed in one groove of a double grooved pulley which is secured to an indicating pointer; the said pulley is rotated by traction exercised upon a second cable having at the end ai drawing button or knob.

,(z) A reaction spring is further mounted on thesaid double-grooved pulley in order to diminish t-he effort of traction which is necessary to: rotate `the said float, andenable the use of the indicating or gauging device in the casein which the path of the cable comprises a certain number of elbows of small.

radius.

The following description, with reference to the appended drawings which are given by way oit-example. sets forth an embodiment of my said invention.

Y Fig. l is asectional view of the gauging or .level indicating device. and, Y

Fig. 2 is a correspondingplanV View. Figs. 3 and lvareirespective sections on the lines 3'-3and of Fig. l. j. f Fig. is'a sectional view of the indicating .dial on the line 5-5 of Fig. l.

The vindicating device comprises a cylin-V der. l, designated as the plunger,` which consists of perforated sheet metal having the immersed. Upon the internal face of the said cylinder, and projecting therefrom, `is the helical ramp l7 Fig. l. Within the said plunger is provided a movable element con-V sisting of the float 2 which is vertically slidable on the upright 3. The latter has a rectangular cross section, and co-operates with a. suitable channel oflike section which is formed in the said float but which has a` slightly larger size7 to provide for the vertical motion of the float without friction.y rlhe said float isv not only guidedin its verg tical `movement lby the said upright, but it further participates in the rotation which is in'iparted to the latter. j rlhe said float is provided with a project-ing member 4t consist-ing of a plate which is soldered to thetopy of the float. Supposing` the said upright 3 to occupy the position i" shown in Fig. l, with the receptacle empty,th e

rfloat will be situated at the lower part of the plunger, as shown in the dotted lines, and the projecting member vwill have the yposition which isv shown in the section Fig. 3.*.The

said upright will have a well-defined position which is designated as the dead centre.

` Vi/Yhen the. receptacle is lilled, the tloatv wil rise with the liquid, whileotherwise maintaining the same position, i. e. the projecting `member of the float. will remain in the posiwill in factbe produced since the angle of Contact 'otl the` projection and the ramp is Vgreaterthan 450. ln this event. the said upright 'with the, shaft 5 will have Amoved through an angle a. i

- lt will be noted. that veachpheightof theV liquid corresponds to vanoperation lin which the device is rotated'through a given angle. In the particular case in which the receptacle" eoY ioni

is full of liquid,v i. efthe level ofthe liquid is vat the top of the plunger, the angle will bel 21T, representing a' complete rotation. i'

Y The amount ofv rotation of the shaft 5. starting from the dead centre,"will depend AuponY the height of the liquid in the receptacle and hence upon its volume. A stop-piece 8 limits the action of the spring 7, so that the said upright shall never exceed the dead point.

.The shaft 5 is rotated by means of a cable 9 forming part of a Bowden power transmission device 9". One end of the said cable is attached to a pulley 9, and the other end ot the cable is disposed in the groove 10 of a pulley 10 which is secured to its shaft upon which is lixed the pointer .11 of the indicating dial. Ina second Vgroove 10b in the pulle y1() is disposed a second cable which issues from the dial at 13 and has mounted at the enda drawing knob 14. The dial is provi-ded with a graduated scale showing in a direct manner the number of liters of liquid remaining in the said receptacle, and the said dia-l is mounted upon Vthe instrument board, in the case of motor vehicles or aeroplanes.

' By' drawing upon the knob 14, the cable is unwcund from the groove 10", and the pulley 10 is thus rotated. The end of the Bowden cable will thus be wound in the groove 10,

so that the pulley 9 will turn in the clockwise direction.

f VThe operation ofthe apparatus is as follows:

With the apparatus in the inoperative position, the volute spring 7 maintains the upright- 3 in the position ofthe dead centre; The pointer on the said dial now indicates dead centre, ,and the said drawing knob is in contact with the dial.

Vlienthe operator is to make a measurement, he draws upon the said knob, thusV drawingfout the cable, .and the latter will rotate both the pulley 10 of the dial and the pulley 9 of the plunger. ,This rotation stops Vwhen the projection 4 of the float comes into contact with the said ramp. The operator then takes the reading by observing the scale division which is in coincidence with the pointer. After taking the reading, he releases the said knob, and the spring 7 will restore the whole to the inoperative position.

To facilitate the functioning of the apparatus, and chiefly in the case in which the path oi' the Bowden device comprises a certain number of elbows of'slight curvature, I prefer to `employ a react-ion spring 15 disposed upon the pulley 10,` within the case of the said dial, said spring being antagonistic to the traction exercised when the operator `draws upon the said knob, `the spring thus acting in the same direction as the spring 7;

' rEhe spring 15 may have any desired range of action, and in particular, I prefer to give the spring 7 a tension whichis 1/5 that of the spring 15.v f

That I claim is 1. A level indicating apparatus for receptacles containing liquids, comprising a perforated cylinder having the same height as the said receptacle, a rotatable upright cothe said loat and adapted to enter into contact with said ramp when the said upright is rotated, a pulley for rotating the said upright-,an indicating dial, a pointer coopeiat- Y ing therewith, a pulley for operating the pointer, a Bowden power transmission device interposed between the two pulleys, and manually operated means for rotating the pointer operating pulley.

A level indicating apparatus `for receptacles containing liquids, comprising a pei'- iorated cylinder having the same height as the said receptacle, a rotatable upright coaxial with said cylinder, afloat slidable on the said upright, a helical ramp disposed within the said cylinder, a tappet secured to the said float and adapt-ed to lenter into contact with the said ramp, an indicating dial, a pointer cooperating therewith, meanswhereby the angular displacement of said pointer shall be controlled by the angularl displacement of the said upright, means including said iirst named means for the distant cons trol ofthe rotation of the said upright, means tor returning the upright to the initial po- Y sition, and means for returning said pointer to the initial position and cooperating with the said means provided upon the cylinder for the return of the upright to the initial position.

tacles containing liquids, comprising a periorated cylinder having the saine height as the said receptacle, a rotatable upright co- A level indicatingapparatus for recepaxial with said cylinder, a iioat slidable on i the said upright, a helical ramp disposed within the said cylinder, a. tappet secured to the said float and adapted to enter Vinto contact with said ramp, a pulley secured tothe c upper end of the said upright and situated at the exterior ot' the said cylinder`a reaction spring secured to said pulley, an indicating dial, a pointer cooperating therewith, a. pulley for operating` the said pointer, a Bowden powertransmission 'devicel interposed between the two pulleys, a reaction spring mounted upon the pulley of the indicator, and means igor rotating the last named pulley.

4. A level indicating apparatus for receptacles containing liquids,comprising a perforated cylinder having the same height as the said receptacle, a rotatable upright coaxial with said cylinder, a loat slidable on the said upright,a helical ramp disposed witliinthe said cylinder, a tappet secured to the said float and adapted to enter into contact with said ramp, a pulley keyed to the I Able grooved pulley for operating the 'l pointer, a. Bowden power transmission device interposed between thel rtwo pulleys and whereofthe cable is attached at one end to the said pulley mounted on the upright and 5 at the other end to the .indicator pulley, u

second cable disposed in the second groove oi' the pulley of the said' indicating` dial, a knob lattached to the outer end of the second cable for drawing upon'the latter, and' a reactionV spring mounted upon the pulley of the indicating dial.

In testimony that claim 'the yforegoing as my invention, I have-signed my lnaine hereto.

' JACQUES GIRARDET'. 

